/*
 * Copyright madding.me.
 */
package com.madding.shared.lang;

import java.math.BigInteger;

/**
 * 类MathUtil.java的实现描述：包装<code>java.lang.Math</code>的工具类
 * 
 * @author madding.lip May 7, 2012 5:42:43 PM
 */
public class MathUtil {

    /**
     * The <code>double</code> value that is closer than any other to <i>e</i>, the base of the natural logarithms.
     */
    public static double getE() {
        return Math.E;
    }

    /**
     * The <code>double</code> value that is closer than any other to <i>pi</i>, the ratio of the circumference of a
     * circle to its diameter.
     */
    public static double getPI() {
        return Math.PI;
    }

    /**
     * Returns the trigonometric sine of an angle. Special cases:
     * <ul>
     * <li>If the argument is NaN or an infinity, then the result is NaN.</li>
     * <li>If the argument is zero, then the result is a zero with the same sign as the argument.</li>
     * </ul>
     * <p>
     * A result must be within 1 ulp of the correctly rounded result. Results must be semi-monotonic.
     * </p>
     * 
     * @param a an angle, in radians.
     * @return the sine of the argument.
     */
    public static double sin(double a) {
        return Math.sin(a);
    }

    /**
     * Returns the trigonometric cosine of an angle. Special cases:
     * <ul>
     * <li>If the argument is NaN or an infinity, then the result is NaN.</li>
     * </ul>
     * <p>
     * A result must be within 1 ulp of the correctly rounded result. Results must be semi-monotonic.
     * </p>
     * 
     * @param a an angle, in radians.
     * @return the cosine of the argument.
     */
    public static double cos(double a) {
        return Math.cos(a);
    }

    /**
     * Returns the trigonometric tangent of an angle. Special cases:
     * <ul>
     * <li>If the argument is NaN or an infinity, then the result is NaN.</li>
     * <li>If the argument is zero, then the result is a zero with the same sign as the argument.</li>
     * </ul>
     * <p>
     * A result must be within 1 ulp of the correctly rounded result. Results must be semi-monotonic.
     * </p>
     * 
     * @param a an angle, in radians.
     * @return the tangent of the argument.
     */
    public static double tan(double a) {
        return Math.tan(a);
    }

    /**
     * Returns the arc sine of an angle, in the range of -<i>pi</i>/2 through <i>pi</i>/2. Special cases:
     * <ul>
     * <li>If the argument is NaN or its absolute value is greater than 1, then the result is NaN.</li>
     * <li>If the argument is zero, then the result is a zero with the same sign as the argument.</li>
     * </ul>
     * <p>
     * A result must be within 1 ulp of the correctly rounded result. Results must be semi-monotonic.
     * </p>
     * 
     * @param a the value whose arc sine is to be returned.
     * @return the arc sine of the argument.
     */
    public static double asin(double a) {
        return Math.asin(a);
    }

    /**
     * Returns the arc cosine of an angle, in the range of 0.0 through <i>pi</i>. Special case:
     * <ul>
     * <li>If the argument is NaN or its absolute value is greater than 1, then the result is NaN.</li>
     * </ul>
     * <p>
     * A result must be within 1 ulp of the correctly rounded result. Results must be semi-monotonic.
     * </p>
     * 
     * @param a the value whose arc cosine is to be returned.
     * @return the arc cosine of the argument.
     */
    public static double acos(double a) {
        return Math.acos(a);
    }

    /**
     * Returns the arc tangent of an angle, in the range of -<i>pi</i>/2 through <i>pi</i>/2. Special cases:
     * <ul>
     * <li>If the argument is NaN, then the result is NaN.</li>
     * <li>If the argument is zero, then the result is a zero with the same sign as the argument.</li>
     * </ul>
     * <p>
     * A result must be within 1 ulp of the correctly rounded result. Results must be semi-monotonic.
     * </p>
     * 
     * @param a the value whose arc tangent is to be returned.
     * @return the arc tangent of the argument.
     */
    public static double atan(double a) {
        return Math.atan(a);
    }

    /**
     * Converts an angle measured in degrees to an approximately equivalent angle measured in radians. The conversion
     * from degrees to radians is generally inexact.
     * 
     * @param angdeg an angle, in degrees
     * @return the measurement of the angle <code>angdeg</code> in radians.
     * @since 1.2
     */
    public static double toRadians(double angdeg) {
        return Math.toRadians(angdeg);
    }

    /**
     * Converts an angle measured in radians to an approximately equivalent angle measured in degrees. The conversion
     * from radians to degrees is generally inexact; users should <i>not</i> expect <code>cos(toRadians(90.0))</code> to
     * exactly equal <code>0.0</code>.
     * 
     * @param angrad an angle, in radians
     * @return the measurement of the angle <code>angrad</code> in degrees.
     * @since 1.2
     */
    public static double toDegrees(double angrad) {
        return Math.toDegrees(angrad);
    }

    /**
     * Returns Euler's number <i>e</i> raised to the power of a <code>double</code> value. Special cases:
     * <ul>
     * <li>If the argument is NaN, the result is NaN.</li>
     * <li>If the argument is positive infinity, then the result is positive infinity.</li>
     * <li>If the argument is negative infinity, then the result is positive zero.</li>
     * </ul>
     * <p>
     * A result must be within 1 ulp of the correctly rounded result. Results must be semi-monotonic.
     * </p>
     * 
     * @param a the exponent to raise <i>e</i> to.
     * @return the value <i>e</i><sup><code>a</code></sup>, where <i>e</i> is the base of the natural logarithms.
     */
    public static double exp(double a) {
        return Math.exp(a);
    }

    /**
     * Returns the natural logarithm (base <i>e</i>) of a <code>double</code> value. Special cases:
     * <ul>
     * <li>If the argument is NaN or less than zero, then the result is NaN.</li>
     * <li>If the argument is positive infinity, then the result is positive infinity.</li>
     * <li>If the argument is positive zero or negative zero, then the result is negative infinity.</li>
     * </ul>
     * <p>
     * A result must be within 1 ulp of the correctly rounded result. Results must be semi-monotonic.
     * </p>
     * 
     * @param a a number greater than <code>0.0</code>.
     * @return the value ln&nbsp;<code>a</code>, the natural logarithm of <code>a</code>.
     */
    public static double log(double a) {
        return Math.log(a);
    }

    /**
     * Returns the correctly rounded positive square root of a <code>double</code> value. Special cases:
     * <ul>
     * <li>If the argument is NaN or less than zero, then the result is NaN.</li>
     * <li>If the argument is positive infinity, then the result is positive infinity.</li>
     * <li>If the argument is positive zero or negative zero, then the result is the same as the argument.</li>
     * </ul>
     * Otherwise, the result is the <code>double</code> value closest to the true mathematical square root of the
     * argument value.
     * 
     * @param a a value. <!--@return the value of &radic;&nbsp;<code>a</code>.-->
     * @return the positive square root of <code>a</code>. If the argument is NaN or less than zero, the result is NaN.
     */
    public static double sqrt(double a) {
        return Math.sqrt(a);
    }

    /**
     * Computes the remainder operation on two arguments as prescribed by the IEEE 754 standard. The remainder value is
     * mathematically equal to <code>f1&nbsp;-&nbsp;f2</code>&nbsp;&times;&nbsp;<i>n</i>, where <i>n</i> is the
     * mathematical integer closest to the exact mathematical value of the quotient <code>f1/f2</code>, and if two
     * mathematical integers are equally close to <code>f1/f2</code>, then <i>n</i> is the integer that is even. If the
     * remainder is zero, its sign is the same as the sign of the first argument. Special cases:
     * <ul>
     * <li>If either argument is NaN, or the first argument is infinite, or the second argument is positive zero or
     * negative zero, then the result is NaN.</li>
     * <li>If the first argument is finite and the second argument is infinite, then the result is the same as the first
     * argument.</li>
     * </ul>
     * 
     * @param f1 the dividend.
     * @param f2 the divisor.
     * @return the remainder when <code>f1</code> is divided by <code>f2</code>.
     */
    public static double IEEEremainder(double f1, double f2) {
        return Math.IEEEremainder(f1, f2);
    }

    /**
     * Returns the smallest (closest to negative infinity) <code>double</code> value that is not less than the argument
     * and is equal to a mathematical integer. Special cases:
     * <ul>
     * <li>If the argument value is already equal to a mathematical integer, then the result is the same as the
     * argument.</li>
     * <li>If the argument is NaN or an infinity or positive zero or negative zero, then the result is the same as the
     * argument.</li>
     * <li>If the argument value is less than zero but greater than -1.0, then the result is negative zero.</li>
     * </ul>
     * Note that the value of <code>Math.ceil(x)</code> is exactly the value of <code>-Math.floor(-x)</code>.
     * 
     * @param a a value. <!--@return the value &lceil;&nbsp;<code>a</code>&nbsp;&rceil;.-->
     * @return the smallest (closest to negative infinity) floating-point value that is not less than the argument and is
     * equal to a mathematical integer.
     */
    public static double ceil(double a) {
        return Math.ceil(a);
    }

    /**
     * Returns the largest (closest to positive infinity) <code>double</code> value that is not greater than the
     * argument and is equal to a mathematical integer. Special cases:
     * <ul>
     * <li>If the argument value is already equal to a mathematical integer, then the result is the same as the
     * argument.</li>
     * <li>If the argument is NaN or an infinity or positive zero or negative zero, then the result is the same as the
     * argument.</li>
     * </ul>
     * 
     * @param a a value. <!--@return the value &lfloor;&nbsp;<code>a</code>&nbsp;&rfloor;.-->
     * @return the largest (closest to positive infinity) floating-point value that is not greater than the argument and
     * is equal to a mathematical integer.
     */
    public static double floor(double a) {
        return Math.floor(a);
    }

    /**
     * Returns the <code>double</code> value that is closest in value to the argument and is equal to a mathematical
     * integer. If two <code>double</code> values that are mathematical integers are equally close, the result is the
     * integer value that is even. Special cases:
     * <ul>
     * <li>If the argument value is already equal to a mathematical integer, then the result is the same as the
     * argument.</li>
     * <li>If the argument is NaN or an infinity or positive zero or negative zero, then the result is the same as the
     * argument.</li>
     * </ul>
     * 
     * @param a a <code>double</code> value.
     * @return the closest floating-point value to <code>a</code> that is equal to a mathematical integer.
     */
    public static double rint(double a) {
        return Math.rint(a);
    }

    /**
     * Converts rectangular coordinates (<code>x</code>,&nbsp;<code>y</code>) to polar (r,&nbsp;<i>theta</i>). This
     * method computes the phase <i>theta</i> by computing an arc tangent of <code>y/x</code> in the range of -<i>pi</i>
     * to <i>pi</i>. Special cases:
     * <ul>
     * <li>If either argument is NaN, then the result is NaN.</li>
     * <li>If the first argument is positive zero and the second argument is positive, or the first argument is positive
     * and finite and the second argument is positive infinity, then the result is positive zero.</li>
     * <li>If the first argument is negative zero and the second argument is positive, or the first argument is negative
     * and finite and the second argument is positive infinity, then the result is negative zero.</li>
     * <li>If the first argument is positive zero and the second argument is negative, or the first argument is positive
     * and finite and the second argument is negative infinity, then the result is the <code>double</code> value closest
     * to <i>pi</i>.</li>
     * <li>If the first argument is negative zero and the second argument is negative, or the first argument is negative
     * and finite and the second argument is negative infinity, then the result is the <code>double</code> value closest
     * to -<i>pi</i>.</li>
     * <li>If the first argument is positive and the second argument is positive zero or negative zero, or the first
     * argument is positive infinity and the second argument is finite, then the result is the <code>double</code> value
     * closest to <i>pi</i>/2.</li>
     * <li>If the first argument is negative and the second argument is positive zero or negative zero, or the first
     * argument is negative infinity and the second argument is finite, then the result is the <code>double</code> value
     * closest to -<i>pi</i>/2.</li>
     * <li>If both arguments are positive infinity, then the result is the <code>double</code> value closest to
     * <i>pi</i>/4.</li>
     * <li>If the first argument is positive infinity and the second argument is negative infinity, then the result is
     * the <code>double</code> value closest to 3<i>pi</i>/4.</li>
     * <li>If the first argument is negative infinity and the second argument is positive infinity, then the result is
     * the <code>double</code> value closest to -<i>pi</i>/4.</li>
     * <li>If both arguments are negative infinity, then the result is the <code>double</code> value closest to
     * -3<i>pi</i>/4.</li>
     * </ul>
     * <p>
     * A result must be within 2 ulps of the correctly rounded result. Results must be semi-monotonic.
     * </p>
     * 
     * @param y the ordinate coordinate
     * @param x the abscissa coordinate
     * @return the <i>theta</i> component of the point (<i>r</i>,&nbsp;<i>theta</i>) in polar coordinates that
     * corresponds to the point (<i>x</i>,&nbsp;<i>y</i>) in Cartesian coordinates.
     */
    public static double atan2(double y, double x) {
        return Math.atan2(y, x);
    }

    /**
     * Returns the value of the first argument raised to the power of the second argument. Special cases:
     * <ul>
     * <li>If the second argument is positive or negative zero, then the result is 1.0.</li>
     * <li>If the second argument is 1.0, then the result is the same as the first argument.</li>
     * <li>If the second argument is NaN, then the result is NaN.</li>
     * <li>If the first argument is NaN and the second argument is nonzero, then the result is NaN.</li>
     * <li>If
     * <ul>
     * <li>the absolute value of the first argument is greater than 1 and the second argument is positive infinity, or</li>
     * <li>the absolute value of the first argument is less than 1 and the second argument is negative infinity,</li>
     * </ul>
     * then the result is positive infinity.</li>
     * <li>If
     * <ul>
     * <li>the absolute value of the first argument is greater than 1 and the second argument is negative infinity, or</li>
     * <li>the absolute value of the first argument is less than 1 and the second argument is positive infinity,</li>
     * </ul>
     * then the result is positive zero.</li>
     * <li>If the absolute value of the first argument equals 1 and the second argument is infinite, then the result is
     * NaN.</li>
     * <li>If
     * <ul>
     * <li>the first argument is positive zero and the second argument is greater than zero, or</li>
     * <li>the first argument is positive infinity and the second argument is less than zero,</li>
     * </ul>
     * then the result is positive zero.</li>
     * <li>If
     * <ul>
     * <li>the first argument is positive zero and the second argument is less than zero, or</li>
     * <li>the first argument is positive infinity and the second argument is greater than zero,</li>
     * </ul>
     * then the result is positive infinity.</li>
     * <li>If
     * <ul>
     * <li>the first argument is negative zero and the second argument is greater than zero but not a finite odd
     * integer, or</li>
     * <li>the first argument is negative infinity and the second argument is less than zero but not a finite odd
     * integer,</li>
     * </ul>
     * then the result is positive zero.</li>
     * <li>If
     * <ul>
     * <li>the first argument is negative zero and the second argument is a positive finite odd integer, or</li>
     * <li>the first argument is negative infinity and the second argument is a negative finite odd integer,</li>
     * </ul>
     * then the result is negative zero.</li>
     * <li>If
     * <ul>
     * <li>the first argument is negative zero and the second argument is less than zero but not a finite odd integer,
     * or</li>
     * <li>the first argument is negative infinity and the second argument is greater than zero but not a finite odd
     * integer,</li>
     * </ul>
     * then the result is positive infinity.</li>
     * <li>If
     * <ul>
     * <li>the first argument is negative zero and the second argument is a negative finite odd integer, or</li>
     * <li>the first argument is negative infinity and the second argument is a positive finite odd integer,</li>
     * </ul>
     * then the result is negative infinity.</li>
     * <li>If the first argument is finite and less than zero
     * <ul>
     * <li>if the second argument is a finite even integer, the result is equal to the result of raising the absolute
     * value of the first argument to the power of the second argument</li>
     * <li>if the second argument is a finite odd integer, the result is equal to the negative of the result of raising
     * the absolute value of the first argument to the power of the second argument</li>
     * <li>if the second argument is finite and not an integer, then the result is NaN.</li>
     * </ul>
     * </li>
     * <li>If both arguments are integers, then the result is exactly equal to the mathematical result of raising the
     * first argument to the power of the second argument if that result can in fact be represented exactly as a
     * <code>double</code> value.</li>
     * </ul>
     * <p>
     * (In the foregoing descriptions, a floating-point value is considered to be an integer if and only if it is finite
     * and a fixed point of the method {@link #ceil <tt>ceil</tt>} or, equivalently, a fixed point of the method
     * {@link #floor <tt>floor</tt>}. A value is a fixed point of a one-argument method if and only if the result of
     * applying the method to the value is equal to the value.)
     * </p>
     * <p>
     * A result must be within 1 ulp of the correctly rounded result. Results must be semi-monotonic.
     * </p>
     * 
     * @param a the base.
     * @param b the exponent.
     * @return the value <code>a<sup>b</sup></code>.
     */
    public static double pow(double a, double b) {
        return Math.pow(a, b);
    }

    /**
     * Returns the closest <code>int</code> to the argument. The result is rounded to an integer by adding 1/2, taking
     * the floor of the result, and casting the result to type <code>int</code>. In other words, the result is equal to
     * the value of the expression:
     * <p>
     * 
     * <pre>
     * (int) Math.floor(a + 0.5f)
     * </pre>
     * 
     * </p>
     * <p>
     * Special cases:
     * <ul>
     * <li>If the argument is NaN, the result is 0.</li>
     * <li>If the argument is negative infinity or any value less than or equal to the value of
     * <code>Integer.MIN_VALUE</code>, the result is equal to the value of <code>Integer.MIN_VALUE</code>.</li>
     * <li>If the argument is positive infinity or any value greater than or equal to the value of
     * <code>Integer.MAX_VALUE</code>, the result is equal to the value of <code>Integer.MAX_VALUE</code>.</li>
     * </ul>
     * </p>
     * 
     * @param a a floating-point value to be rounded to an integer.
     * @return the value of the argument rounded to the nearest <code>int</code> value.
     * @see java.lang.Integer#MAX_VALUE
     * @see java.lang.Integer#MIN_VALUE
     */
    public static int round(float a) {
        return Math.round(a);
    }

    /**
     * Returns the closest <code>long</code> to the argument. The result is rounded to an integer by adding 1/2, taking
     * the floor of the result, and casting the result to type <code>long</code>. In other words, the result is equal to
     * the value of the expression:
     * <p>
     * 
     * <pre>
     * (long) Math.floor(a + 0.5d)
     * </pre>
     * 
     * </p>
     * <p>
     * Special cases:
     * <ul>
     * <li>If the argument is NaN, the result is 0.</li>
     * <li>If the argument is negative infinity or any value less than or equal to the value of
     * <code>Long.MIN_VALUE</code>, the result is equal to the value of <code>Long.MIN_VALUE</code>.</li>
     * <li>If the argument is positive infinity or any value greater than or equal to the value of
     * <code>Long.MAX_VALUE</code>, the result is equal to the value of <code>Long.MAX_VALUE</code>.</li>
     * </ul>
     * </p>
     * 
     * @param a a floating-point value to be rounded to a <code>long</code>.
     * @return the value of the argument rounded to the nearest <code>long</code> value.
     * @see java.lang.Long#MAX_VALUE
     * @see java.lang.Long#MIN_VALUE
     */
    public static long round(double a) {
        return Math.round(a);
    }

    /**
     * Returns a <code>double</code> value with a positive sign, greater than or equal to <code>0.0</code> and less than
     * <code>1.0</code>. Returned values are chosen pseudorandomly with (approximately) uniform distribution from that
     * range.
     * <p>
     * When this method is first called, it creates a single new pseudorandom-number generator, exactly as if by the
     * expression <blockquote>
     * 
     * <pre>
     * new java.util.Random
     * </pre>
     * 
     * </blockquote> This new pseudorandom-number generator is used thereafter for all calls to this method and is used
     * nowhere else.
     * </p>
     * <p>
     * This method is properly synchronized to allow correct use by more than one thread. However, if many threads need
     * to generate pseudorandom numbers at a great rate, it may reduce contention for each thread to have its own
     * pseudorandom-number generator.
     * </p>
     * 
     * @return a pseudorandom <code>double</code> greater than or equal to <code>0.0</code> and less than
     * <code>1.0</code>.
     * @see java.util.Random#nextDouble()
     */
    public static double random() {
        return Math.random();
    }

    /**
     * Returns the absolute value of an <code>int</code> value. If the argument is not negative, the argument is
     * returned. If the argument is negative, the negation of the argument is returned.
     * <p>
     * Note that if the argument is equal to the value of <code>Integer.MIN_VALUE</code>, the most negative
     * representable <code>int</code> value, the result is that same value, which is negative.
     * </p>
     * 
     * @param a the argument whose absolute value is to be determined
     * @return the absolute value of the argument.
     * @see java.lang.Integer#MIN_VALUE
     */
    public static int abs(int a) {
        return Math.abs(a);
    }

    /**
     * Returns the absolute value of a <code>long</code> value. If the argument is not negative, the argument is
     * returned. If the argument is negative, the negation of the argument is returned.
     * <p>
     * Note that if the argument is equal to the value of <code>Long.MIN_VALUE</code>, the most negative representable
     * <code>long</code> value, the result is that same value, which is negative.
     * </p>
     * 
     * @param a the argument whose absolute value is to be determined
     * @return the absolute value of the argument.
     * @see java.lang.Long#MIN_VALUE
     */
    public static long abs(long a) {
        return Math.abs(a);
    }

    /**
     * Returns the absolute value of a <code>float</code> value. If the argument is not negative, the argument is
     * returned. If the argument is negative, the negation of the argument is returned. Special cases:
     * <ul>
     * <li>If the argument is positive zero or negative zero, the result is positive zero.</li>
     * <li>If the argument is infinite, the result is positive infinity.</li>
     * <li>If the argument is NaN, the result is NaN.</li>
     * </ul>
     * In other words, the result is the same as the value of the expression:
     * <p>
     * 
     * <pre>
     * Float.intBitsToFloat(0x7fffffff &amp; Float.floatToIntBits(a))
     * </pre>
     * 
     * </p>
     * 
     * @param a the argument whose absolute value is to be determined
     * @return the absolute value of the argument.
     */
    public static float abs(float a) {
        return Math.abs(a);
    }

    /**
     * Returns the absolute value of a <code>double</code> value. If the argument is not negative, the argument is
     * returned. If the argument is negative, the negation of the argument is returned. Special cases:
     * <ul>
     * <li>If the argument is positive zero or negative zero, the result is positive zero.</li>
     * <li>If the argument is infinite, the result is positive infinity.</li>
     * <li>If the argument is NaN, the result is NaN.</li>
     * </ul>
     * In other words, the result is the same as the value of the expression:
     * <p>
     * <code>Double.longBitsToDouble((Double.doubleToLongBits(a)&lt;&lt;1)&gt;&gt;&gt;1)</code>
     * </p>
     * 
     * @param a the argument whose absolute value is to be determined
     * @return the absolute value of the argument.
     */
    public static double abs(double a) {
        return Math.abs(a);
    }

    /**
     * Returns the greater of two <code>int</code> values. That is, the result is the argument closer to the value of
     * <code>Integer.MAX_VALUE</code>. If the arguments have the same value, the result is that same value.
     * 
     * @param a an argument.
     * @param b another argument.
     * @return the larger of <code>a</code> and <code>b</code>.
     * @see java.lang.Long#MAX_VALUE
     */
    public static int max(int a, int b) {
        return Math.max(a, b);
    }

    /**
     * Returns the greater of two <code>long</code> values. That is, the result is the argument closer to the value of
     * <code>Long.MAX_VALUE</code>. If the arguments have the same value, the result is that same value.
     * 
     * @param a an argument.
     * @param b another argument.
     * @return the larger of <code>a</code> and <code>b</code>.
     * @see java.lang.Long#MAX_VALUE
     */
    public static long max(long a, long b) {
        return Math.max(a, b);
    }

    /**
     * Returns the greater of two <code>float</code> values. That is, the result is the argument closer to positive
     * infinity. If the arguments have the same value, the result is that same value. If either value is NaN, then the
     * result is NaN. Unlike the the numerical comparison operators, this method considers negative zero to be strictly
     * smaller than positive zero. If one argument is positive zero and the other negative zero, the result is positive
     * zero.
     * 
     * @param a an argument.
     * @param b another argument.
     * @return the larger of <code>a</code> and <code>b</code>.
     */
    public static float max(float a, float b) {
        return Math.max(a, b);
    }

    /**
     * Returns the greater of two <code>double</code> values. That is, the result is the argument closer to positive
     * infinity. If the arguments have the same value, the result is that same value. If either value is NaN, then the
     * result is NaN. Unlike the the numerical comparison operators, this method considers negative zero to be strictly
     * smaller than positive zero. If one argument is positive zero and the other negative zero, the result is positive
     * zero.
     * 
     * @param a an argument.
     * @param b another argument.
     * @return the larger of <code>a</code> and <code>b</code>.
     */
    public static double max(double a, double b) {
        return Math.max(a, b);
    }

    /**
     * Returns the smaller of two <code>int</code> values. That is, the result the argument closer to the value of
     * <code>Integer.MIN_VALUE</code>. If the arguments have the same value, the result is that same value.
     * 
     * @param a an argument.
     * @param b another argument.
     * @return the smaller of <code>a</code> and <code>b</code>.
     * @see java.lang.Long#MIN_VALUE
     */
    public static int min(int a, int b) {
        return Math.min(a, b);
    }

    /**
     * Returns the smaller of two <code>long</code> values. That is, the result is the argument closer to the value of
     * <code>Long.MIN_VALUE</code>. If the arguments have the same value, the result is that same value.
     * 
     * @param a an argument.
     * @param b another argument.
     * @return the smaller of <code>a</code> and <code>b</code>.
     * @see java.lang.Long#MIN_VALUE
     */
    public static long min(long a, long b) {
        return Math.min(a, b);
    }

    /**
     * Returns the smaller of two <code>float</code> values. That is, the result is the value closer to negative
     * infinity. If the arguments have the same value, the result is that same value. If either value is NaN, then the
     * result is NaN. Unlike the the numerical comparison operators, this method considers negative zero to be strictly
     * smaller than positive zero. If one argument is positive zero and the other is negative zero, the result is
     * negative zero.
     * 
     * @param a an argument.
     * @param b another argument.
     * @return the smaller of <code>a</code> and <code>b.</code>
     */
    public static float min(float a, float b) {
        return Math.min(a, b);
    }

    /**
     * Returns the smaller of two <code>double</code> values. That is, the result is the value closer to negative
     * infinity. If the arguments have the same value, the result is that same value. If either value is NaN, then the
     * result is NaN. Unlike the the numerical comparison operators, this method considers negative zero to be strictly
     * smaller than positive zero. If one argument is positive zero and the other is negative zero, the result is
     * negative zero.
     * 
     * @param a an argument.
     * @param b another argument.
     * @return the smaller of <code>a</code> and <code>b</code>.
     */
    public static double min(double a, double b) {
        return Math.min(a, b);
    }

    public static boolean isPowerOfTwo(int intValue) {
        if (intValue == 0) {
            return false;
        }

        while ((intValue & 1) == 0) {
            intValue = intValue >>> 1;
        }

        return intValue == 1;
    }

    public static boolean isPowerOfTwo(long longValue) {
        if (longValue == 0L) {
            return false;
        }

        while ((longValue & 1L) == 0L) {
            longValue = longValue >>> 1;
        }

        return longValue == 1L;
    }

    public static boolean isPowerOfTwo(BigInteger bintValue) {
        int bitIndex = bintValue.getLowestSetBit();

        if (bitIndex < 0) {
            return false;
        }

        return bintValue.clearBit(bitIndex).equals(BigInteger.ZERO);
    }
}
